AtCoder Regular Contest 072
F
Dam
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原题
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Problem Statement

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You are in charge of controlling a dam. The dam can store at most $L$ liters of water. Initially, the dam is empty. Some amount of water flows into the dam every morning, and any amount of water may be discharged every night, but this amount needs to be set so that no water overflows the dam the next morning.

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It is known that $v_i$ liters of water at $t_i$ degrees Celsius will flow into the dam on the morning of the $i$-th day. You are wondering about the maximum possible temperature of water in the dam at noon of each day, under the condition that there needs to be exactly $L$ liters of water in the dam at that time. For each $i$, find the maximum possible temperature of water in the dam at noon of the $i$-th day. Here, consider each maximization separately, that is, the amount of water discharged for the maximization of the temperature on the $i$-th day, may be different from the amount of water discharged for the maximization of the temperature on the $j$-th day $(j≠i)$.

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Also, assume that the temperature of water is not affected by anything but new water that flows into the dam. That is, when $V_1$ liters of water at $T_1$ degrees Celsius and $V_2$ liters of water at $T_2$ degrees Celsius are mixed together, they will become $V_1+V_2$ liters of water at $\frac{T_1*V_1+T_2*V_2}{V_1+V_2}$ degrees Celsius, and the volume and temperature of water are not affected by any other factors.

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Constraints

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  • $1≤ N ≤ 5*10^5$
  • $1≤ L ≤ 10^9$
  • $0≤ t_i ≤ 10^9(1≤i≤N)$
  • $1≤ v_i ≤ L(1≤i≤N)$
  • $v_1 = L$
  • $L$, each $t_i$ and $v_i$ are integers.
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Input

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Input is given from Standard Input in the following format:

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N L
t_1 v_1
t_2 v_2
:
t_N v_N

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Output

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Print $N$ lines. The $i$-th line should contain the maximum temperature such that it is possible to store $L$ liters of water at that temperature in the dam at noon of the $i$-th day.

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Each of these values is accepted if the absolute or relative error is at most $10^{-6}$.

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样例

Input #1
3 10
10 10
20 5
4 3
Output #1
10.0000000
15.0000000
13.2000000
- On the first day, the temperature of water in the dam is always $10$ degrees: the temperature of the only water that flows into the dam on the first day. - $10$ liters of water at $15$ degrees of Celsius can be stored on the second day, by discharging $5$ liters of water on the night of the first day, and mix the remaining water with the water that flows into the dam on the second day. - $10$ liters of water at $13.2$ degrees of Celsius can be stored on the third day, by discharging $8$ liters of water on the night of the first day, and mix the remaining water with the water that flows into the dam on the second and third days.
Input #2
4 15
0 15
2 5
3 6
4 4
Output #2
0.0000000
0.6666667
1.8666667
2.9333333
Input #3
4 15
1000000000 15
9 5
8 6
7 4
Output #3
1000000000.0000000
666666669.6666666
400000005.0000000
293333338.8666667
Although the temperature of water may exceed $100$ degrees Celsius, we assume that water does not vaporize.
题目信息
题号
arc072_d
时间限制
3 s
内存限制
256 MB

题面与样例版权归 AtCoder 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。